The objective of this project is the biochemical characterization of sperm maturation. During epididymal transit, sperm undergo maturation which includes transformation from a nonmotile to a motile form. A hypothesis presented herein, and which will be tested, is that both modification of the sperm plasma membrane surface and a marked increase in intracellular NAD concentration are necessary before sperm can become motile. Specific biochemical comparisons of testicular and cauda epididymal ram sperm will involve: 1. The phosphatidylinositol, glycolipid and ganglioside content of the intact sperm and purified plasma membrane preparations. 2. The NAD content of the sperm and the enzymes involved in its synthesis and metabolic conversion to other compounds. The final set of experiments will involve isolation of sperm from at least four locations in the epididymis, quantitative determinations of both the percentage of motile sperm and sperm velocity and measuring the biochemical features listed above. These experiments will establish the relationship among alterations of membrane lipids and cellular NAD concentration associated with epididymal maturation of sperm and the initiation of progressive motility. They will not establish the "cause" of the initiation of progressive motility but will define changes required before progressive motility can be achieved.